EM waves absorption properties of nitrogenous porous carbon derived from PANI fiber clusters carbonization

The carbon source, graphitization degree and microstructure of pure carbon materials have strong effects on their electrical conductivity, impedance matching and electromagnetic (EM) waves absorption properties. A novel microstructure nitrogenous porous carbon (NPC) material with excellent EM waves absorption properties was synthesized by carbonizing polyaniline (PANI) fiber clusters. When the filler loading is only 30 wt%, the widest effective absorption bandwidth (EAB) reached 5.5 GHz from 12.41 GHz to 17.91 GHz (almost the entire Ku band) with a thickness of only 1.5 mm and the EAB/thickness was up to 3.67 GHz/mm, which is not inferior or even better than many composites with complex structure. The nitrogen atoms in NPC lattice reduced its graphitization degree. The synergistic effect of optimized impedance matching and enhanced dielectric loss improved EM waves absorption of NPC. The EM waves dissipation mechanisms of NPC material mainly include dipole polarization, interface polarization and conductance loss. The synthesized NPC is a potential EM waves absorption material.